Pectoral muscles

Mm. pectorales superficiales; M. pectoralis profundus

Muscles of the ventral thorax joining the sternum to the humerus; adductors of the thoracic limb.

Draft, not yet reviewed by a veterinarian. Content may contain errors. It is published so the community can review it.

This piece is a schematic shape, not a scan: there is no freely licensed model for this structure yet.

3D model of this piece: Vet Atlas procedural musculature, CC BY-SA 4.0

Overview

The dog has two groups:

Superficial pectorals (mm. pectorales superficiales): the descending and transverse pectorals, cranial and superficial.
Deep pectoral (m. pectoralis profundus): larger, caudal and deep to the former.

Superficial pectorals: manubrium and first sternebrae.
Deep pectoral: ventral surface of the sternum and, caudally, the deep abdominal fascia.

Superficial pectorals: crest of the greater tubercle of the humerus; the transverse pectoral continues into the antebrachial fascia.
Deep pectoral: mainly the lesser tubercle of the humerus, with a sheet reaching the greater tubercle.

Adduct the thoracic limb. The deep pectoral also draws the limb caudally and, with the limb planted, pulls the trunk cranially.

Cranial and caudal pectoral nerves (nn. pectorales) from the brachial plexus.